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<b>DB_ENV-&gt;log_printf</b>
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<b><pre>
#include &lt;db.h&gt;
<p>
int
DB_ENV-&gt;log_printf(DB_ENV *env, DB_TXN *txnid, const char *fmt, ...);
</pre></b>
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<b>Description: DB_ENV-&gt;log_printf</b>
<p>The DB_ENV-&gt;log_printf method appends an informational message to the Berkeley DB
database environment log files.</p>
<p>The DB_ENV-&gt;log_printf method allows applications to include information in
the database environment log files, for later review using the
<a href="../utility/db_printlog.html">db_printlog</a> utility.  This method is intended for debugging and
performance tuning.</p>
<p>The DB_ENV-&gt;log_printf method
returns a non-zero error value on failure
and 0 on success.
</p>
<b>Parameters</b> <br>
 <b>txnid</b><ul compact><li>If the logged message refers to an application-specified transaction,
the <b>txnid</b> parameter is a transaction handle returned from
<a href="../api_c/txn_begin.html">DB_ENV-&gt;txn_begin</a>; otherwise NULL.</ul>
 <b>fmt</b><ul compact><li>A format string that specifies how subsequent arguments (or arguments
accessed via the variable-length argument facilities of stdarg(3)) are
converted for output.  The format string may contain any formatting
directives supported by the underlying C library vsnprintf(3)
function.</ul>
<br>
<br><b>Errors</b>
<p>The DB_ENV-&gt;log_printf method
may fail and return one of the following non-zero errors:</p>
<br>
<b>EINVAL</b><ul compact><li>An
invalid flag value or parameter was specified.</ul>
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<br><b>Class</b>
<a href="../api_c/env_class.html">DB_ENV</a>, <a href="../api_c/logc_class.html">DB_LOGC</a>, <a href="../api_c/lsn_class.html">DB_LSN</a>
<br><b>See Also</b>
<a href="../api_c/log_list.html">Logging Subsystem and Related Methods</a>
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